DESCRIPTION (Applicant's Description) The telomere/telomerase hypothesis of aging and cancer is supported by the following observations: telomeres shorten with cellular senescence in vitro and with aging in vivo; telomerase expression is detected in tumor cells but not in most normal cells; telomerase inhibition in tumor cells leads to growth arrest or cell death. Recently, significant advances have made it possible to experimentally test many aspects of this hypothesis. These include the cloning of the human telomerase RNA, its catalytic protein Components, a telomerase associated protein, the identification of telomere binding proteins, and the development of telomerase and telomere assays. Further understanding of the pathways connecting telomere shortening, cellular senescence, telomerase expression and cancer should have significant impact on the development of novel therapeutic approaches for cancer and agerelated diseases. The proposed symposium, "Telomerase and telomere dynamics in cancer and aging", will focus in depth on the most rapidly emerging areas in the field of telomere and telomerase biology. Special emphasis will be placed on studies relevant to both the aging and cancer disciplines as well as those which explore the relationships between the two disciplines. Specifically, the following areas will be covered: (1) lower model organisms such as yeast and protozoa for understanding the genetics, biochemistry, cell and molecular biology of telomeres and telomerase; (2) mouse models of telomere and telomerase biology related to aging and cancer; (3) basic research and clinical human studies on the role of telomeres and telomerase in aging and cancer. The symposium will consist of 7 formal sessions which will include both invited and contributed presentations. In addition to having highly regarded scientists in the field as participants, time slots will also be available for speakers selected from submitted abstracts and for those with latebreaking results. Similar to the Gordon/FASEB meetings, there will be formal sessions each morning and evening and informal time each afternoon to facilitate interactions and discussions. This meeting will bring together both basic scientists investigating telomere/telomerase biology and clinicians interested in more translational aspects of aging and cancer research, to present new discoveries and to discuss the most latebreaking findings.